public void TransitionExample()
{
var currentState = new CartStateEmpty() as ICartState;
//add some products from the UI, say
currentState = TransitionAddProduct(currentState, Product.ProductX);
currentState = TransitionAddProduct(currentState, Product.ProductY);
//pay from the UI, say
var cartStateActive = currentState as CartStateActive; //CAST!
if (cartStateActive == null)
{
Assert.Fail("Expected CartStateActive here");
}
const decimal paidAmount = 12.34m;
currentState = cartStateActive.Pay(paidAmount);
var cartStatePaid = currentState as CartStatePaid; //CAST!
if (cartStatePaid == null)
{
Assert.Fail("Expected CartStatePaid here");
}
var itemCount = cartStatePaid.Items.Count();
Assert.That(itemCount, Is.EqualTo(2));
var actualPaidAmount = cartStatePaid.Amount;
Assert.That(actualPaidAmount, Is.EqualTo(paidAmount));
}
public void TransitionExample()
{
var currentState = new CartStateEmpty() as ICartState;
//add some products from the UI, say
currentState = TransitionAddProduct(currentState, Product.ProductX);
currentState = TransitionAddProduct(currentState, Product.ProductY);
//pay from the UI, say
const decimal paidAmount = 12.34m;
currentState = currentState.Transition(
cartStateEmpty => cartStateEmpty,
cartStateActive => cartStateActive.Pay(paidAmount),
cartStatePaid => cartStatePaid);
var isPaidState = currentState.Func(cartStateEmpty => false, cartStateActive => false, cartStatePaid => true);
Assert.IsTrue(isPaidState);
var itemCount = currentState.Func(cartStateEmpty => -1, cartStateActive => -1, cartStatePaid => cartStatePaid.Items.Count());
Assert.That(itemCount, Is.EqualTo(2));
var actualPaidAmount = currentState.Func(cartStateEmpty => -1, cartStateActive => -1, cartStatePaid => cartStatePaid.Amount);
Assert.That(actualPaidAmount, Is.EqualTo(paidAmount));
}
public ICartState VisitEmpty(CartStateEmpty empty)
{
return empty;
}
public ICartState VisitEmpty(CartStateEmpty empty)
{
empty.AddItem(productToAdd); return empty;
}
public void WhenEmptyCartAndAddItemExpectActiveCartWithOneItem()
{
var emptyCart = new CartStateEmpty();
var newState = emptyCart.Add(Product.ProductX);
var isActiveState = newState.Func(cartStateEmpty => false, cartStateActive => true, cartStatePaid => false);
Assert.IsTrue(isActiveState);
var itemCount = newState.Func(cartStateEmpty => -1, cartStateActive => cartStateActive.Items.Count(), cartStatePaid => -1);
Assert.That(itemCount, Is.EqualTo(1));
}
public void WhenEmptyCartAndAddItemExpectActiveCartWithOneItem()
{
// arrange
var emptyCart = new CartStateEmpty();
// act
var newState = emptyCart.Add(Product.ProductX);
// assert
var activeState = newState as CartStateActive; //CAST!
if (activeState != null)
{
var itemCount = activeState.Items.Count();
Assert.That(itemCount, Is.EqualTo(1));
}
else
{
Assert.Fail("Expect ActiveState");
}
}
